Summary

In version 8.0 of MongoDB we’ll make it so that new sharded clusters can be created and existing clusters can be expanded by running new instances of mongod without any required command line arguments.

To do so we’ll make the following changes:

The --router flag (router role) is always enabled and cannot be disabled.
The --replSet argument becomes an implicitly provided (enabled) argument.
The --shardsvr,  --configsvr flags (and roles) default to being enabled.
If you specify any one of them individually then they default to being disabled in order to let users selectively designate a mongod as a dedicated shard server or a dedicated config server replica set member.

Additional details about Bootstrapping New Clusters, growing clusters, and upgrading clusters can be found in the architecture document. 

Motivation

We want to provide a way for non-Atlas users to start a 1 shard cluster by default when they spin up a new mongodb cluster by running a ./mongod. This will provide them the same default experience as Atlas users. 

Most teams have been informed in the PD for this epic: https://jira.mongodb.org/browse/WRITING-11413
however, I wanted to make sure I click the downstream changes summary buttons as a friendly reminder about the change.

Description of Linked Ticket

Summary

In version 8.0 of MongoDB we’ll make it so that new sharded clusters can be created and existing clusters can be expanded by running new instances of mongod without any required command line arguments.

To do so we’ll make the following changes:

• The --router flag (router role) is always enabled and cannot be disabled.
• The --replSet argument becomes an implicitly provided (enabled) argument.
• The --shardsvr,  --configsvr flags (and roles) default to being enabled.
• If you specify any one of them individually then they default to being disabled in order to let users selectively designate a mongod as a dedicated shard server or a dedicated config server replica set member.

Additional details about Bootstrapping New Clusters, growing clusters, and upgrading clusters can be found in the architecture document. 

Motivation

We want to provide a way for non-Atlas users to start a 1 shard cluster by default when they spin up a new mongodb cluster by running a ./mongod. This will provide them the same default experience as Atlas users.